There have now been three separate fires among roughly 20,000 Tesla Model S electric luxury sedans on the world's highways.

The most recent one, two days ago, seems to have set off a fresh round of Internet fulmination--combined with much opining on what the news would do to the falling stock price of Tesla Motors [NSDQ:TSLA].

So let's pull together all the facts, and sort out what we know from what we still need to find out.

WHAT WE KNOW

Fire # 1

The first fire, on October 1, occurred in Kent, Washington, outside Seattle. It apparently occurred after the Model S ran over a piece of road debris later described as a "curved section that fell off a semi-trailer."

That item punched a 3-inch hole through the 1/4-inch-thick armor plate protecting the pack, with a force of 25 tons, according to a report by Tesla. The car alerted the driver of a fault, and he pulled over and exited the car.

The National Highway Traffic Safety Administration (NHTSA) released a statement on Thursday say that it had "not found evidence at this time that would indicate the recent battery fire involving a Tesla Model S was the result of a vehicle safety defect or non-compliance with federal safety standards.”

Fire # 2

The second fire, on October 18, was in Mérida, a city in the Mexican Yucatán. It apparently occurred after the Model S driver jumped a curb, took out several feet of a concrete wall, and then hit a tree.

The third fire, on Wednesday (November 6), occurred on Interstate 24 near Smyrna, Tennessee. Ironically, that town contains both a car assembly plant and a lithium-ion cell assembly facility for the Nissan Leaf electric car.

Tesla issued this statement: “We have been in contact with the driver, who was not injured and believes the car saved his life. Our team is on its way to Tennessee to learn more about what happened in the accident.”

The National Highway Traffic Safety Administration issued a statement, saying, "NHTSA will contact the local authorities who are looking into the incident to determine if there are vehicle safety implications that merit agency action."